Search Results (18)

Squamosa Promoter-Binding Protein Like (SPL) is a critical transcription factor that plays a significant role in regulating plant growth and development. Mining the coconut SPL family offers valuable insights into the regulation of important agronomic traits, including the length of the juvenile phase. In this study, 25 CnSPLs were identified and were classified into eight subfamilies. Analysis of gene structure and conserved protein motifs indicated a high conservation of CnSPLs within the same subfamilies; however, variations in protein structure and gene length were observed across different subfamilies. Gene expansion analysis indicated that most gene members within subfamilies originated from duplications of the same genomic segment, and transposable element insertion contributed to the divergence of gene sequences within these subfamilies. Characterization of the miR156 target sequence in SPL transcripts revealed that subfamilies IV to VIII contained these sequences, while subfamilies I to III did not. In both coconut and 14 other plant species, some SPLs lost their miR156-binding loci due to gene structure variations. The gene expression profiles revealed significant divergence between miR156-targeted and non-targeted CnSPLs; the former exhibited low expression levels in the endosperm, while the latter showed comparable expression across all tissues. Notably, CnSPL15A demonstrated steadily increasing expression levels in leaves throughout successive leaf primordia and significantly promoted flowering when overexpressed in Arabidopsis. Transient expression assays and 5′ RACE confirmed that CnSPLs are targeted by miR156. This study establishes a foundation for investigating the evolutionary characteristics of CnSPLs and provides a theoretical framework for analyzing the functions of key CnSPLs involved in the coconut flowering control pathway. Full article

Sugar-Will-Eventually-be-Exported Transporters (SWEETs) play a crucial role in sugar transport in plants, mediating both plant development and stress responses. Despite their importance, there has been limited research characterizing the functional characteristics of CnSWEET genes in coconut (Cocos nucifera). In this study, we conducted a systematic analysis of SWEET genes in coconut using bioinformatics, subcellular localization studies, in silico promoter analysis, and functional assays with yeast mutants. A total of 16 CnSWEET genes were identified and grouped into four clades. Clade I contained the highest number of genes (eight), derived from four pairs of duplicated genomic segments. In contrast, the other clades had fewer genes (one to four) compared to those in Arabidopsis and other species in the Arecaceae family. An extensive analysis of gene expansion using MSCanX indicated significant divergence in gene expansion patterns, both between and within monocots and dicots, as well as among closely related species within the same family. Notable variations in conserved protein motifs and the number of transmembrane helices (TMHs) were detected within Clade I compared to other clades, affecting the subcellular localization of CnSWEET proteins. Specifically, seven TMHs were associated with proteins located in the cell membrane, while CnSWEET2A, which had five TMHs, was found in both the cell membrane and cytosol. Promoter analysis revealed that some CnSWEET genes contained endosperm or seed specific motifs associated with specific endosperm expression, consistent with expression patterns observed in transcriptome data. Functional analysis of five CnSWEET genes, with transcript sequences supported by transcriptome data, was conducted using yeast mutant complementation assays. This analysis demonstrated diverse transport activities for sucrose, fructose, glucose, galactose, and mannose. Our findings provide valuable insights into the functional diversity of SWEET genes in coconuts and their potential roles in stress responses and plant development. Full article

The makapuno coconut endosperm is distinguished by its soft and irregular texture, in contrast to the solid endosperm of regular coconuts. To establish a scientific foundation for studying makapuno coconuts, callus was induced from makapuno endosperm using a combination of plant growth regulators. The induction was successful, and the resulting callus was subsequently subcultured for further study. Transcriptome sequencing of the makapuno callus identified 429 differentially expressed genes (DEGs), with 273 upregulated and 156 downregulated, compared to callus derived from regular coconut endosperm. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that these DEGs were involved in key metabolic pathways, including fructose and mannose metabolism, carbon fixation in photosynthetic organisms, galactose metabolism, and amino sugar and nucleotide sugar metabolism. Furthermore, lipid content analysis of the makapuno callus revealed a significantly higher total lipid level compared to regular callus, with notable differences in the levels of specific fatty acids, such as myristic acid, palmitic acid, and linoleic acid. This study establishes a novel platform for molecular biological research on makapuno coconuts and provides valuable insights into the molecular mechanisms underlying the formation of makapuno callus tissue. The findings also lay the groundwork for future research aimed at elucidating the unique properties of makapuno endosperm and exploring its potential applications. Full article

Procuring high-grade RNA from mature coconut tissues is a tricky and labor-intensive process due to the intricate scaffold of polysaccharides, polyphenols, lipids, and proteins that form firm complexes with nucleic acids. However, we have effectively developed a novel method for the first time, letting the retrieval of high-grade RNA from the roots, endosperm, and mesocarp of mature coconut trees take place. In this method, we exploited dichloromethane as a replacement to phenol/chloroform for RNA recovery from mature coconut tissues. The amount of high-grade RNA acquired from the roots of mature coconut trees was 120.7 µg/g, with an A260/280 ratio of 1.95. Similarly, the mature coconut mesocarp yielded 134.6 µg/g FW of quality RNA with A260/280 ratio of 1.98, whereas the mature coconut endosperm produced 120.4 µg/g FW of quality RNA with A260/280 ratio of 2.01. Furthermore, the RNA isolation using the dichloromethane method exhibited excellent performance in downstream experiments, particularly in RT-PCR for cDNA production and amplification. On the contrary, the RNA plant kit, TRIZOL, and Cetyl Trimethyl Ammonium Bromide (CTAB) methods were unsuccessful in isolating substantial quantities of RNA with exceptional purities from the mentioned coconut tissues. In view of these findings, we conclude that the newly developed method will be pivotal in effectively extracting RNA with high purity from mature coconut tissues. Full article

Cocos nucifera L. is one of the most cultivated palm trees in the world since it is used to obtain both raw materials and food. From a human point of view, the coconut fruit is a very valuable product, producing an aromatic and tasty liquid endosperm (coconut water) containing high levels of sugars, amino acids and other molecules of nutritional and nutraceutical value. Most of the chemical composition studies conducted on coconut to date have focused on the determination of fatty acid content in coconut oil and the extension of the shelf life of coconut water. Despite the economic importance of this species, the maturation of the coconut fruit is a complex biological process scarcely studied from the metabolic approach and biochemical changes occurring during fruit maturation are not well-known. The objective of this study is to investigate and elucidate the metabolic changes that occur during the maturation process of coconut (Cocos nucifera L.) fruits, specifically focusing on the liquid endosperm of the Yucatan green dwarf variety. In this study, the liquid endosperm of coconut fruits at the immature, intermediate and mature stages have been analyzed through an untargeted metabolomics approach by ultra performance liquid chromatography coupled to high resolution mass spectrometry (UPLC-HRMS). A total of 591 spectrometric features were detected and the corresponding identified compounds were classified into 24 chemical classes. The principal component analysis (PCA) showed segregation among the samples, according to their stage of maturation. Most of the metabolites detected were related to the metabolism of flavonoids, carbohydrates and organooxygen compounds. Pathway analysis showed that sphingolipid, starch and sucrose metabolisms were among the most over-accumulated during ripening, followed by the metabolism of glyoxylates and dicarboxylates and the metabolism of amino acids such as alanine, aspartate and glutamate, and others. This is the first study that focuses on elucidating the metabolic profiles of the liquid endosperm of coconut Yucatan green dwarf variety during three stages of maturation with an untargeted metabolomics approach through UPLC-MS. Full article

Cocos nucifera L. is a crop grown in the humid tropics. It is grouped into two classes of varieties: dwarf and tall; regardless of the variety, the endosperm of the coconut accumulates carbohydrates in the early stages of maturation and fatty acids in the later stages, although the biochemical factors that determine such behavior remain unknown. We used tandem mass tagging with synchronous precursor selection (TMT-SPS-MS3) to analyze the proteomes of solid endosperms from Yucatan green dwarf (YGD) and Mexican pacific tall (MPT) coconut cultivars. The analysis was conducted at immature, intermediate, and mature development stages to better understand the regulation of carbohydrate and lipid metabolisms. Proteomic analyses showed 244 proteins in YGD and 347 in MPT; from these, 155 proteins were shared between both cultivars. Furthermore, the proteomes related to glycolysis, photosynthesis, and gluconeogenesis, and those associated with the biosynthesis and elongation of fatty acids, were up-accumulated in the solid endosperm of MPT, while in YGD, they were down-accumulated. These results support that carbohydrate and fatty acid metabolisms differ among the developmental stages of the solid endosperm and between the dwarf and tall cultivars. This is the first proteomics study comparing different stages of maturity in two contrasting coconut cultivars and may help in understanding the maturity process in other palms. Full article

Coconut (Cocos nucifera L.) is widely recognized as one of nature’s most beneficial plants. Makapuno, a special type of coconut with a soft, jelly-like endosperm, is a high-value commercial coconut and an expensive delicacy with a high cost of planting material. The embryo rescue technique is a very useful tool to support mass propagation of makapuno coconut. Nevertheless, transplanting the seedlings is a challenge due to poor root development, which results in the inability of the plant to acclimatize. In this study, primary root excision was used in makapuno to observe the effects of primary root excision on lateral root development. The overall results showed that seedlings with roots excised had a significantly higher number of lateral roots, and shoot length also increased significantly. Using de novo transcriptome assembly and differential gene expression analysis, we identified 512 differentially expressed genes in the excised and intact root samples. ERF071, encoding an ethylene-responsive transcription factor, was identified as a highly expressed gene in excised roots compared to intact roots, and was considered a candidate gene associated with lateral root formation induced by root excision in makapuno coconut. This study provides insight into the mechanism and candidate genes involved in the development of lateral roots in coconut, which may be useful for the future breeding and mass propagation of makapuno coconut through tissue culture. Full article

Makapuno is a natural mutant coconut cultivar with jelly-like endosperm. Here, we investigated the nutritional compositions, active ingredients, and antioxidant activities of Makapuno meat and water. The contents of macronutrients, sugars, vitamins, amino acids, and fatty acids were reported. We found that Makapuno meat has higher dietary fiber with lower protein and fat content compared to normal coconut meat. Medium-chain fatty acids were the major fat component of Makapuno meat and water. Phytochemical analysis revealed that while flavonoid content was lower, the total phenolic, alkaloid, and tannin contents of Makapuno meat were comparable with those of mature coconut. However, Makapuno water contained higher alkaloid content when compared to mature and young coconuts. The antioxidant activities, as examined by DPPH, FRAP, and ABTS assays, showed that Makapuno meat and water had antioxidant activities, and Makapuno water exhibited protective activity against DNA damage. Hence, this research provides the nutraceutical importance of Makapuno, which could be used in the food industry. Full article

Black soldier fly (BSF, Hermetia illucens) larvae are considered as insects with a high potential to convert organic waste into high-value products. The objective of this study was to investigate the growth performance, waste reduction efficiency, and nutritional composition of BSF reared on different ratios of coconut endosperm (C) and soybean curd residue (S), with or without supplementation, compared to standard diets (Gainesville: G and starter chicken diet: CK). Seven-day-old larvae were randomly divided into eight experimental groups (G, CK, and three different ratios of C and S with or without supplementation) with three replicates with an equal weight of larvae. The supplement contained calcium, phosphorus, amino acids, and a mineral–vitamin premix which was formulated to correlate with CK. Each replicate was terminated, measured, and evaluated when 40% of larvae had reached prepupal stage. The highest larval weight gain was presented in BSF fed CK, followed by those fed coconut endosperm and soybean curd residue at a ratio of 20:80 (C20S80), and coconut endosperm and soybean curd residue at a ratio of 50:50 (C50S50) without supplementation (numbers after C and S represent their percentage in the formulation; p < 0.001). Harvesting was delayed in the BSF fed C80S20 with and without supplementation (p < 0.001). The number of total larvae and prepupae was not significantly different between groups (p > 0.05). The greatest waste reduction efficiency was observed in the G, C50S50, and C20S80 groups without supplementation (p < 0.001). All groups with supplementation had a higher proportion of ash in both larvae and prepupae compared to non-supplemented groups (p < 0.001), but lower growth performance. The highest percentage of crude protein in larvae was presented in the Gainesville and C20S80 groups followed by the CK and C50S50 groups (p < 0.001). Equal proportions of C and S without supplementation are suggested as a rearing substrate. However, growth performance was lower than for CK; therefore, further studies could investigate cost-efficient techniques to promote this parameter. Full article

Coconut endosperm waste (CEW) was treated by Rhizopus oligosporus via in situ and ex situ fermentations together with bioconversion into valuable black soldier fly larval biomass. The ex situ fermentation could overall enrich the nutritional compositions of CEW by hydrolyzing its complex organic polymers and exuding assimilable nutrients to enhance the black soldier fly larvae (BSFL) growth. Nevertheless, the larval gut bacteria were competing with Rhizopus oligosporus in in situ fermentation, derailing the hydrolysis processes and larval growth. Accordingly, the highest growth rates achieved were around 0.095 g/day, as opposed to only 0.065 g/day whilst using 0.5 wt% of Rhizopus oligosporus to perform ex situ and in situ fermentations, respectively. These were also underpinned by the greater amount of total CEW consumed when employing ex situ fermentation, with comparable metabolic costs to feeding on in situ-fermented CEW. The mature BSFL were subsequently harvested and the amounts of protein and lipid produced were assessed in terms of their feasibility for biodiesel production. While the statistical analyses showed that the larval protein yields derived from both fermentation modes were insignificant, the BSFL could attain higher lipid and protein productivities upon feeding with ex situ- rather than in situ-fermented CEW mediums. Better yet, the larval biodiesel quality measured in terms of the fatty acid methyl ester composition were not varied significantly by Rhizopus oligosporus through the fermentation process. Thereby, the presence of 1.0 wt% Rhizopus oligosporus was considered optimum to perform ex situ fermentation, giving rise to the acceptable growth of BSFL loaded with the highest lipid yield and productivity for producing biodiesel and protein simultaneously. Full article

Oftentimes, the employment of entomoremediation to reduce organic wastes encounters ubiquitous shortcomings, i.e., ineffectiveness to valorize recalcitrant organics in wastes. Considering the cost-favorability, a fermentation process can be employed to facilitate the degradation of biopolymers into smaller organics, easing the subsequent entomoremediation process. However, the efficacy of in situ fermentation was found impeded by the black soldier fly larvae (BSFL) in the current study to reduce coconut endosperm waste (CEW). Indeed, by changing into ex situ fermentation, in which the fungal Rhizopus oligosporus was permitted to execute fermentation on CEW prior to the larval feeding, the reduction of CEW was significantly enhanced. In this regard, the waste reduction index of CEW by BSFL was almost doubled as opposed to in situ fermentation, even with the inoculation of merely 0.5 wt % of Rhizopus oligosporus. Moreover, with only 0.02 wt % of fungal inoculation size to execute the ex situ fermentation on CEW, it could spur BSFL growth by about 50%. Finally, from the statistical correlation study using principal component analysis, the presence of Rhizopus oligosporus in a range of 0.5–1.0 wt % was regarded as optimum to ferment CEW via ex situ mode, prior to the valorization by BSFL in reducing the CEW. Full article

Recently, worldwide researchers have been focusing on exploiting of black soldier fly larval (BSFL) biomass to serve as the feed mediums for farmed animals, including aquaculture farming, in order to assuage the rising demands for protein sources. In this study, yeast was introduced into coconut endosperm waste (CEW) whilst serving as the feeding medium to rear BSFL in simultaneously performed in situ fermentation. It was found that at a 2.5 wt% yeast concentration, the total biomass gained, growth rate and rearing time were improved to 1.145 g, 0.085 g/day and 13.5 days, respectively. In terms of solid waste reduction, the inoculation of yeast over 0.5 wt% in CEW was able to achieve more than 50% overall degradation, with the waste reduction indexes (WRIs) ranging from 0.038 to 0.040 g/day. Disregarding the concentration of yeast introduced, the protein productivity from 20 BSFL was enhanced from only 0.018 g/day (the control) to 0.025 g/day with the presence of yeast at arbitrary concentrations. On the other hand, the larval protein yield was fortified from the control (28%) to a highest value of 35% with the presence of a mere 0.02 wt% yeast concentration. To summarize, the inclusion of a minimal amount of yeast into CEW for in situ fermentation ultimately enhanced the growth of BSFL, as well as its protein yield and productivity. Full article

Coconut testa is the thin brown colored outer skin of coconut endosperm. It is often peeled off from the kernel during coconut processing due to unfavorable brown colour it might impart on finished products. An attempt was made to utilize coconut testa to produce defatted flour as a substitute for wheat flour in bakery products. Aim of this study was to compare the total phenolic content (TPC) and ferric reducing antioxidant power (FRAP) of coconut testa flour of four local cultivars namely san raman (SR), gon thembili (GT), ran thembili (RT), TallxTall (TxT) against the commercial hybrid (COM) grown in Sri Lanka. Hundred grams of coconut testa flour produced from partially defatted coconut pairings was extracted with 70% ethanol-water mixture. The TPC and FRAP assays were conducted using a 96 well micro plate reader. Percentage yield (%) of crude extracts of SR, RT, GT, TXT and COM were 8.26, 6.87, 7.66, 8.06 and 11.17, respectively. The maximum TPC content was observed in TXT (62.58 ± 5.99 mg GAE/g of extract) while the minimum TPC content was recorded for GT (27.53 ± 4.54 mg GAE/g of extract). The lowest FRAP value was observed for SR (0.26 ± 0.02 mmol FeSO₄/g of extract) while the highest FRAP value was observed for COM (0.67 ± 0.00 mmol FeSO₄/g of extract) variety. In conclusion, coconut testa flour is a rich source of phenolics and antioxidants. The presence of these bioactives would make it a potential functional ingredient in food processing industry. Full article

The aim of this study was to spur the lipid accumulation by larvae of Hermetia illucens or black soldier fly (BSFL) via feeding with yeast fermented medium. The Saccharomyces cerevisiae, a single cell yeast, was introduced at different concentrations (0.02, 0.1, 0.5, 1.0, 2.5 wt %) to execute an in-situ fermentation on coconut endosperm waste. The rearing of BSFL was started simultaneously and the rearing was stopped once the BSFL reached the fifth instar. With the increasing of yeast concentration, the rearing duration of BSFL was shortened from 15.5 to 13.5 days. Moreover, it was found that at 0.5 to 1.0 wt % yeast concentration, the lipid yield and lipid productivity of BSFL were statistically enhanced to their highest peaks, namely, at 49.4% and 0.53 g/day, respectively. With regard to biodiesel composition, BSFL-derived biodiesel contained mainly C12:0, C14:0, C16:0 and C18:1. The higher amount of saturated fatty acids could strengthen the oxidative stability biodiesel produced as compared with non-edible oils or microalgal lipid. At last, the addition of yeast was also found to improve the waste reduction index of coconut endosperm waste (CEW) from 0.31 to 0.40 g/day, heralding the capability of BSFL to valorize organic waste via bioconversion into its biomass to serve as a feedstock for biodiesel production. Full article

Primarily produced via transesterification of lipid sources, fatty acid methyl ester (FAME) of biodiesel derived from insect larvae has gained momentum in a great deal of research done over other types of feedstock. From the self-harvesting nature of black soldier fly larvae (BSFL), research had, however, only concentrated on the harvest of BSFL on sixth instar. Through rearing BSFL on coconut endosperm waste (CEW), 100 BSFL were harvested at the fifth and sixth instar, then modification on CEW with mixed-bacteria powder was carried out. It was found that the fifth instar BSFL had 34% lipid content, which was 8% more than the sixth instar. Both instars had similar corrected protein contents around 35–38%. The sixth instar BSFL contained around 19% of chitin, which was about 11% more than the fifth instar. Biodiesel products from both instars showed no differences in terms of FAME content. With modification on CEW, at 0.5 wt% of mixed-bacteria powder concentration, the maximum waste-to-biomass conversion (WBC) and protein conversion (PC) were achieved at 9% and 60%, respectively. Moreover, even with the shorter fermentation time frame of CEW, it did not affect the development of BSFL in terms of its WBC and PC when fed with 14 and 21 days fermented medium. FAME from all groups set, which predominantly constituted about C12:0 at around 60%, followed by C14:0 at around 15%, C16:0, and C18:1 both at 10% on average. Lastly, the FAME yield from BSFL was improved from 25% (sixth instar) to 33% (fifth instar) and showed its highest at 38.5% with modification on raw CEW with 0.5 wt% mixed-bacteria powder and fermented for 21 days. Thus, harvesting BSFL at earlier instar is more beneficial and practical, as it improves the FAME yield from the BSFL biomass. Full article